diff options
Diffstat (limited to 'drivers/rtc/rtc-sa1100.c')
| -rw-r--r-- | drivers/rtc/rtc-sa1100.c | 388 |
1 files changed, 388 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-sa1100.c b/drivers/rtc/rtc-sa1100.c new file mode 100644 index 000000000000..83b2bb480a16 --- /dev/null +++ b/drivers/rtc/rtc-sa1100.c @@ -0,0 +1,388 @@ +/* + * Real Time Clock interface for StrongARM SA1x00 and XScale PXA2xx + * + * Copyright (c) 2000 Nils Faerber + * + * Based on rtc.c by Paul Gortmaker + * + * Original Driver by Nils Faerber <nils@kernelconcepts.de> + * + * Modifications from: + * CIH <cih@coventive.com> + * Nicolas Pitre <nico@cam.org> + * Andrew Christian <andrew.christian@hp.com> + * + * Converted to the RTC subsystem and Driver Model + * by Richard Purdie <rpurdie@rpsys.net> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#include <linux/platform_device.h> +#include <linux/module.h> +#include <linux/rtc.h> +#include <linux/init.h> +#include <linux/fs.h> +#include <linux/interrupt.h> +#include <linux/string.h> +#include <linux/pm.h> + +#include <asm/bitops.h> +#include <asm/hardware.h> +#include <asm/irq.h> +#include <asm/rtc.h> + +#ifdef CONFIG_ARCH_PXA +#include <asm/arch/pxa-regs.h> +#endif + +#define TIMER_FREQ CLOCK_TICK_RATE +#define RTC_DEF_DIVIDER 32768 - 1 +#define RTC_DEF_TRIM 0 + +static unsigned long rtc_freq = 1024; +static struct rtc_time rtc_alarm; +static spinlock_t sa1100_rtc_lock = SPIN_LOCK_UNLOCKED; + +static int rtc_update_alarm(struct rtc_time *alrm) +{ + struct rtc_time alarm_tm, now_tm; + unsigned long now, time; + int ret; + + do { + now = RCNR; + rtc_time_to_tm(now, &now_tm); + rtc_next_alarm_time(&alarm_tm, &now_tm, alrm); + ret = rtc_tm_to_time(&alarm_tm, &time); + if (ret != 0) + break; + + RTSR = RTSR & (RTSR_HZE|RTSR_ALE|RTSR_AL); + RTAR = time; + } while (now != RCNR); + + return ret; +} + +static irqreturn_t sa1100_rtc_interrupt(int irq, void *dev_id, + struct pt_regs *regs) +{ + struct platform_device *pdev = to_platform_device(dev_id); + struct rtc_device *rtc = platform_get_drvdata(pdev); + unsigned int rtsr; + unsigned long events = 0; + + spin_lock(&sa1100_rtc_lock); + + rtsr = RTSR; + /* clear interrupt sources */ + RTSR = 0; + RTSR = (RTSR_AL | RTSR_HZ) & (rtsr >> 2); + + /* clear alarm interrupt if it has occurred */ + if (rtsr & RTSR_AL) + rtsr &= ~RTSR_ALE; + RTSR = rtsr & (RTSR_ALE | RTSR_HZE); + + /* update irq data & counter */ + if (rtsr & RTSR_AL) + events |= RTC_AF | RTC_IRQF; + if (rtsr & RTSR_HZ) + events |= RTC_UF | RTC_IRQF; + + rtc_update_irq(&rtc->class_dev, 1, events); + + if (rtsr & RTSR_AL && rtc_periodic_alarm(&rtc_alarm)) + rtc_update_alarm(&rtc_alarm); + + spin_unlock(&sa1100_rtc_lock); + + return IRQ_HANDLED; +} + +static int rtc_timer1_count; + +static irqreturn_t timer1_interrupt(int irq, void *dev_id, + struct pt_regs *regs) +{ + struct platform_device *pdev = to_platform_device(dev_id); + struct rtc_device *rtc = platform_get_drvdata(pdev); + + /* + * If we match for the first time, rtc_timer1_count will be 1. + * Otherwise, we wrapped around (very unlikely but + * still possible) so compute the amount of missed periods. + * The match reg is updated only when the data is actually retrieved + * to avoid unnecessary interrupts. + */ + OSSR = OSSR_M1; /* clear match on timer1 */ + + rtc_update_irq(&rtc->class_dev, rtc_timer1_count, RTC_PF | RTC_IRQF); + + if (rtc_timer1_count == 1) + rtc_timer1_count = (rtc_freq * ((1<<30)/(TIMER_FREQ>>2))); + + return IRQ_HANDLED; +} + +static int sa1100_rtc_read_callback(struct device *dev, int data) +{ + if (data & RTC_PF) { + /* interpolate missed periods and set match for the next */ + unsigned long period = TIMER_FREQ/rtc_freq; + unsigned long oscr = OSCR; + unsigned long osmr1 = OSMR1; + unsigned long missed = (oscr - osmr1)/period; + data += missed << 8; + OSSR = OSSR_M1; /* clear match on timer 1 */ + OSMR1 = osmr1 + (missed + 1)*period; + /* Ensure we didn't miss another match in the mean time. + * Here we compare (match - OSCR) 8 instead of 0 -- + * see comment in pxa_timer_interrupt() for explanation. + */ + while( (signed long)((osmr1 = OSMR1) - OSCR) <= 8 ) { + data += 0x100; + OSSR = OSSR_M1; /* clear match on timer 1 */ + OSMR1 = osmr1 + period; + } + } + return data; +} + +static int sa1100_rtc_open(struct device *dev) +{ + int ret; + + ret = request_irq(IRQ_RTC1Hz, sa1100_rtc_interrupt, SA_INTERRUPT, + "rtc 1Hz", dev); + if (ret) { + printk(KERN_ERR "rtc: IRQ%d already in use.\n", IRQ_RTC1Hz); + goto fail_ui; + } + ret = request_irq(IRQ_RTCAlrm, sa1100_rtc_interrupt, SA_INTERRUPT, + "rtc Alrm", dev); + if (ret) { + printk(KERN_ERR "rtc: IRQ%d already in use.\n", IRQ_RTCAlrm); + goto fail_ai; + } + ret = request_irq(IRQ_OST1, timer1_interrupt, SA_INTERRUPT, + "rtc timer", dev); + if (ret) { + printk(KERN_ERR "rtc: IRQ%d already in use.\n", IRQ_OST1); + goto fail_pi; + } + return 0; + + fail_pi: + free_irq(IRQ_RTCAlrm, NULL); + fail_ai: + free_irq(IRQ_RTC1Hz, NULL); + fail_ui: + return ret; +} + +static void sa1100_rtc_release(struct device *dev) +{ + spin_lock_irq(&sa1100_rtc_lock); + RTSR = 0; + OIER &= ~OIER_E1; + OSSR = OSSR_M1; + spin_unlock_irq(&sa1100_rtc_lock); + + free_irq(IRQ_OST1, dev); + free_irq(IRQ_RTCAlrm, dev); + free_irq(IRQ_RTC1Hz, dev); +} + + +static int sa1100_rtc_ioctl(struct device *dev, unsigned int cmd, + unsigned long arg) +{ + switch(cmd) { + case RTC_AIE_OFF: + spin_lock_irq(&sa1100_rtc_lock); + RTSR &= ~RTSR_ALE; + spin_unlock_irq(&sa1100_rtc_lock); + return 0; + case RTC_AIE_ON: + spin_lock_irq(&sa1100_rtc_lock); + RTSR |= RTSR_ALE; + spin_unlock_irq(&sa1100_rtc_lock); + return 0; + case RTC_UIE_OFF: + spin_lock_irq(&sa1100_rtc_lock); + RTSR &= ~RTSR_HZE; + spin_unlock_irq(&sa1100_rtc_lock); + return 0; + case RTC_UIE_ON: + spin_lock_irq(&sa1100_rtc_lock); + RTSR |= RTSR_HZE; + spin_unlock_irq(&sa1100_rtc_lock); + return 0; + case RTC_PIE_OFF: + spin_lock_irq(&sa1100_rtc_lock); + OIER &= ~OIER_E1; + spin_unlock_irq(&sa1100_rtc_lock); + return 0; + case RTC_PIE_ON: + if ((rtc_freq > 64) && !capable(CAP_SYS_RESOURCE)) + return -EACCES; + spin_lock_irq(&sa1100_rtc_lock); + OSMR1 = TIMER_FREQ/rtc_freq + OSCR; + OIER |= OIER_E1; + rtc_timer1_count = 1; + spin_unlock_irq(&sa1100_rtc_lock); + return 0; + case RTC_IRQP_READ: + return put_user(rtc_freq, (unsigned long *)arg); + case RTC_IRQP_SET: + if (arg < 1 || arg > TIMER_FREQ) + return -EINVAL; + if ((arg > 64) && (!capable(CAP_SYS_RESOURCE))) + return -EACCES; + rtc_freq = arg; + return 0; + } + return -EINVAL; +} + +static int sa1100_rtc_read_time(struct device *dev, struct rtc_time *tm) +{ + rtc_time_to_tm(RCNR, tm); + return 0; +} + +static int sa1100_rtc_set_time(struct device *dev, struct rtc_time *tm) +{ + unsigned long time; + int ret; + + ret = rtc_tm_to_time(tm, &time); + if (ret == 0) + RCNR = time; + return ret; +} + +static int sa1100_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) +{ + memcpy(&alrm->time, &rtc_alarm, sizeof(struct rtc_time)); + alrm->pending = RTSR & RTSR_AL ? 1 : 0; + return 0; +} + +static int sa1100_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) +{ + int ret; + + spin_lock_irq(&sa1100_rtc_lock); + ret = rtc_update_alarm(&alrm->time); + if (ret == 0) { + memcpy(&rtc_alarm, &alrm->time, sizeof(struct rtc_time)); + + if (alrm->enabled) + enable_irq_wake(IRQ_RTCAlrm); + else + disable_irq_wake(IRQ_RTCAlrm); + } + spin_unlock_irq(&sa1100_rtc_lock); + + return ret; +} + +static int sa1100_rtc_proc(struct device *dev, struct seq_file *seq) +{ + seq_printf(seq, "trim/divider\t: 0x%08x\n", RTTR); + seq_printf(seq, "alarm_IRQ\t: %s\n", + (RTSR & RTSR_ALE) ? "yes" : "no" ); + seq_printf(seq, "update_IRQ\t: %s\n", + (RTSR & RTSR_HZE) ? "yes" : "no"); + seq_printf(seq, "periodic_IRQ\t: %s\n", + (OIER & OIER_E1) ? "yes" : "no"); + seq_printf(seq, "periodic_freq\t: %ld\n", rtc_freq); + + return 0; +} + +static struct rtc_class_ops sa1100_rtc_ops = { + .open = sa1100_rtc_open, + .read_callback = sa1100_rtc_read_callback, + .release = sa1100_rtc_release, + .ioctl = sa1100_rtc_ioctl, + .read_time = sa1100_rtc_read_time, + .set_time = sa1100_rtc_set_time, + .read_alarm = sa1100_rtc_read_alarm, + .set_alarm = sa1100_rtc_set_alarm, + .proc = sa1100_rtc_proc, +}; + +static int sa1100_rtc_probe(struct platform_device *pdev) +{ + struct rtc_device *rtc; + + /* + * According to the manual we should be able to let RTTR be zero + * and then a default diviser for a 32.768KHz clock is used. + * Apparently this doesn't work, at least for my SA1110 rev 5. + * If the clock divider is uninitialized then reset it to the + * default value to get the 1Hz clock. + */ + if (RTTR == 0) { + RTTR = RTC_DEF_DIVIDER + (RTC_DEF_TRIM << 16); + printk(KERN_WARNING "rtc: warning: initializing default clock divider/trim value\n"); + /* The current RTC value probably doesn't make sense either */ + RCNR = 0; + } + + rtc = rtc_device_register(pdev->name, &pdev->dev, &sa1100_rtc_ops, + THIS_MODULE); + + if (IS_ERR(rtc)) { + dev_err(&pdev->dev, "Unable to register the RTC device\n"); + return PTR_ERR(rtc); + } + + platform_set_drvdata(pdev, rtc); + + dev_info(&pdev->dev, "SA11xx/PXA2xx RTC Registered\n"); + + return 0; +} + +static int sa1100_rtc_remove(struct platform_device *pdev) +{ + struct rtc_device *rtc = platform_get_drvdata(pdev); + + if (rtc) + rtc_device_unregister(rtc); + + return 0; +} + +static struct platform_driver sa1100_rtc_driver = { + .probe = sa1100_rtc_probe, + .remove = sa1100_rtc_remove, + .driver = { + .name = "sa1100-rtc", + }, +}; + +static int __init sa1100_rtc_init(void) +{ + return platform_driver_register(&sa1100_rtc_driver); +} + +static void __exit sa1100_rtc_exit(void) +{ + platform_driver_unregister(&sa1100_rtc_driver); +} + +module_init(sa1100_rtc_init); +module_exit(sa1100_rtc_exit); + +MODULE_AUTHOR("Richard Purdie <rpurdie@rpsys.net>"); +MODULE_DESCRIPTION("SA11x0/PXA2xx Realtime Clock Driver (RTC)"); +MODULE_LICENSE("GPL"); |